The present invention is directed generally to a device for monitoring the relative point of impact of an object in flight proximal a reference line on a surface. In many applications, it is important to determine whether an object in flight has impacted a surface on a reference line or on one side of the reference line or another. The reference line may be an imaginary line or it may be a line which is visually perceptible. The dimensions of the object, its speed, and distance between the point of impact and the point of observation and the angle of observation may preclude a visual determination of the point of impact by a human observer.
This problem may be encountered in various recreational games which employ a game court defined by boundary markers for example, the games of handball, basketball, baseball, soccer, football and tennis, all of which employ game courts defined by boundary markers in the form of stripes having predetermined widths. Each edge of such a boundary stripe may be considered a reference line. In such applications, a game ball may strike the game court surface proximal an edge of the boundary stripe, making it difficult or impossible to determine whether the ball has landed "in bounds" or "out of bounds". In the game of tennis, a game ball is considered "out of bounds" only if the ball strikes no part of the game court including the boundary stripe. The boundary stripe may be the service box stripe or the base line stripe. The unaided human eye may be unable to determine the point of surface impact of the ball proximal the outer edge of the boundary stripe due to dimensions of the ball, the speed of the ball, and the distance from and angle at which the point of surface impact must be observed.
The purpose of the present invention is to provide a device for monitoring the point of impact of an object in flight proximal a reference line such as the outer edge of a game court boundary stripe, which device is reliable, relatively inexpensive to construct and operate, and which determines whether the point of surface impact of the object is on one side of the reference line or the other by a simple algorithm.